Aquarius
was reconditioned in 1996 and redeployed to the Florida
Keys in 1997. The inset photo shows the laboratory on
the dock before it was towed out to sea and placed in
its current position at Conch Reef.

About
Aquarius

Aquarius is
the only undersea laboratory in the world. It is owned by the National
Oceanic and Atmospheric Administration, or NOAA, and administered
by NOAA's National Undersea Research Program. The facility is operated
by the National Undersea Research Center at the University of North
Carolina at Wilmington. It provides a long-term research platform
and undersea living quarters that allow scientists to stay on the
seafloor for extended periods of time.

Aquarius was
built in Victoria, Texas, in 1986. Originally, it was deployed in
the U.S. Virgin Islands, but was later moved to its current location,
5.6 kilometers (3.5 miles) off Key Largo in the Florida Keys National
Marine Sanctuary. It stands next to deep coral reefs 19 meters (62
feet) below the surface.

The laboratory
has hosted more than 200 scientists representing more than 90 organizations,
including NASA and universities from the United States and several
foreign countries. Aquarius scientists work to understand the changing
ocean and the condition of coral reefs, which are threatened locally,
regionally and globally by increasing amounts of pollution, over-harvesting
of fisheries, disease and climate change.

Science achievements
from Aquarius include discoveries related to the damaging effects
of ultraviolet light on coral reefs, geological studies that use
fossil reefs to better understand the significance of present-day
changes in coral reefs, research that is rewriting the book on how
corals feed, growth studies of important sponges that uncovered
surprising factors affecting their abundance and distribution, water
quality studies to evaluate sources of pollution and long-term studies
of reefs to distinguish between changes caused by natural system
variability and humans.

The Aquarius
system has three elements: a life-support buoy at the surface, the
habitat and a baseplate that secures the habitat to the ocean floor.
The Aquarius habitat has about 37 square meters (400 square feet)
of living and laboratory space.

Near the habitat
are other facilities to assist divers. Two waystations -- the Pinnacle
and the Gazebo -- hold pockets of air. Divers can stop at these
locations to top off their air tanks and talk.

A
diver crouches inside the Pinnacle waystation, where he
can catch a breath of fresh air and top off his tanks.

Aquarius is
an ambient pressure habitat, which means that the interior atmospheric
pressure is equal to the surrounding water pressure. Its main entrance
in the Wet Porch remains open to the ocean, and water is kept out
by the equivalent air pressure inside, much like an air pocket inside
an inverted glass prevents water from completely filling when immersed.
The baseplate rests in approximately 19 meters (62 feet) of water,
with the habitat mounted off the bottom at a depth of approximately
14 meters (47 feet) -- tidal range at the site is between .5 and
1 meter (2 and 3 feet). This operating depth is referred to as "hatch
depth."

The pressure
at 14 meters (47 feet) of seawater is about 2.5 times greater than
the atmospheric pressure found at sea level. At this depth and pressure,
visitors to Aquarius have only about 80 minutes to complete their
stay and return to the surface before they risk experiencing decompression-related
illness. However, the mission inhabitants of Aquarius, known as
“aquanauts," can stay indefinitely and have nearly unlimited bottom
time during their scuba dives from Aquarius. At the end of a mission,
aquanauts undergo a 17-hour decompression that is conducted within
Aquarius itself, while on the bottom. At the end of decompression,
aquanauts exit Aquarius and scuba-dive back to the surface.